The Post-Symposium Field Trip B-2:

DEVONIAN AND CARBONIFEROUS OF THE MORAVIAN KARST (CZECH REPUBLIC) August 7-11, 2003

�����

JINDŘICH HLADIL Institute of Geology, Academy of Sciences Cz.R., Rozvojová 135, 165 02 Prague

GEOLOGICAL SETTING OF THE MORAVIAN KARST

Outlines of Variscan (Late Carboniferous) deformation fabric

The Moravian Karst developed with an erosion section across a thick accumulation of Devonian limestones in central part of Moravia (country), north of Brno (town). The block-structured belt of these limestones is approximately 30 km long, 4 km wide and up to 2 km thick. At least the separate groups of blocks can be observed, because of the fact, that the northern, middle and southern parts have significantly different stratigraphy, deformation style and thermal alteration of rocks. The strongest thermal alterations (and locally also isoclinal faulting) were observed in northwestern part of Moravian Karst, for example, near the Sloup-Šošůvka Caves. An ideal block of the Moravian Karst consists of Devonian limestones with their close underlying and overlying rocks, when all these rocks together were wedged between the partly overthrusted Neoproterozoic crystalline basement (on the west) and partly underthrusted Carboniferous hanging rocks (on the east). This belt of Moravian Karst represents a clockwise rotated and tectonically separated relict of past land promontory that jutted out from hundred kilometers wide Devonian complex of platforms, between the hypothetical Devonian Horákov Bay (on the south) and Konice Bay (north).

The largest and strongest deformation structures (such as folds, or structures after slicing and shearing) originated basically during two late Variscan orogenic deformation events, which developed during Namurian and Westfalian, respectively. However, the first faulting after relatively quiet late extensional Givetian-Frasnian stage appeared as early as with the late Frasnian times and mainly Tournaisian strata and hiatuses provide documents about moderate instability of basements and also volcanic explosions in neighborhoods. Many normal and strike-slip faults are younger that Variscan and originated particularly during the Permian (post-orogenic post-Variscan extensions) and Tertiary ages (reflection of Carpathian orogenic front).

In spite of the fact, that western and eastern margins of the Moravian Karst have tectonically changed contacts on many places, the normal stratigraphic superposition characterizes still at least 60-70 % of inner volume of separate blocks. The Kettner's concept (before the Second War) much exaggerated the slicing and tectonical stacking of limestones and projected the tectonic detachments further into the centers of rigid blocks of reef limestones. In early 20th century, only 'dark-colored Amphipora' and 'light-colored coral limestones' were known and their sedimentary repetitions were often mistakenly considered to be a direct evidence of tectonic stacking. On the other hand, the Dvořák concept (after the Second War) was just opposite. This concept based up to the details on the absence of tectonic translations and tried to explain all structures with minimum of orogenic deformation (mainly by synsedimentary tectonics, modeling the block mosaics 'in situ'). This historical conflict between two geological schools has today rather historical than factual significance, because the modern studies on stratigraphy, facies, petrology, deformation and paleomagnetism can determine the history of separate blocks with relatively good resolution.

A classical question is, what originally were below and above these Moravian Devonian stromatoporoid-coral limestones. The simplified answer is, that below were (and still mostly are) Neoproterozoic granitoids, capped by relicts of Cambrian to Devonian siliciclastic sediments (mostly continental aridic weathering products; riverine floodsheets; rarely deposits from marine ingressions, e.g., Early Cambrian and Emsian, ~ Dalejan). And above, there were locally post-reefal limestones and mainly several kilometers thick Variscan nappe piles (slices of crystalline rocks with Devonian cover, and huge portions of Culmian flysch facies). These Culmian nappe piles were pushed over the limestones in Namurian and limestones were buried under significant load of overlying rocks (~13 km on the north, ~ 6 km in the south). However, these entire piles were significantly dissected even during the Late Carboniferous and also Early Permian times. The limestones of Moravian Karst were consequently uplifted from these great depths of their burial back to the surface.

Guidebook B2 'Moravian Karst' – p. 1

Stromatoporoid-coral limestones of the Devonian age

The Devonian stratigraphic units of limestones can be essentially traced as swelling and undulated belts of N-S strike and E dip, that are traceable on the geological map of detailed scales (1 : 25.000 and less). The total thickness of these stromatoporoid-coral limestones (constructed from maps, boreholes and determined by geophysics) fluctuates from 200-1100 m. Sandy-silty non-carbonate admixture was found rather at the base than in the upper parts of the complex. The same can be judged about little occurrence of dolomite and abundance of micritic sediment. In general, the Devonian limestones of Moravian Karst are very pure calcite rocks, having in average about 5 wt.% of non-carbonate material (airborne dust > aquatic suspensions) and 0.15 wt.% Corg. The maximum temperatures of relatively homogeneous Namurian heating (based on organic matter, illite crystallinity and conodont colors) were 250-150 ºC, with lower values on the south. All fossils in Devonian (and Carboniferous) limestones are considerably well-preserved for the thin-sectioning (with even the delicate microstructural ghosts) but are badly extractable using the hammer or expansion techniques. It is because of the complex deep-burial fine-crystalline mosaics that go through the rock fabrics. The extraction of fossils in the southern part of Moravian Karst is better if compared with the north, owing to relatively shallower burial. However, also on these places the rapid uplift with rock expansion formed numerous healed micro-fractures (CL-imaging), that are disadvantageous for preparation techniques. Better results can be achieved in rocks along hiatuses and bands of microstylolitic sutures, basically due to membranes by clay minerals coating the surface of corals.

Čelechovice Cycle (Čelechovice and Vavřinec Lmst.): Along the northwestern margin of the Moravian Karst are outcrops of Late Eifelian and Early Givetian limestones, which represent the first carbonate banks and reefs that extensively onlapped on the Moravian Block during its early separation stages (Emsian-Tournaisian breakup of Brunnia). These limestones developed from dark-colored transgression facies with Spongioalveolites intermixtus or Scoliopora multispinosa (Čelechovice Limestone) to light-colored reef limestones with big coralla of Favosites gilsoni, Heliolites porosus, or thick branches of Thamnopora tumaefacta (Vavřinec Limestone). This first significant carbonate platform part of the Late-Eifelian to earliest Givetian parasequence is known as the Čelechovice Cycle. The Early/Middle Givetian lowstand tract was marked by extensive erosion, red soils, and locally also with sandstone layers.

Býčí skála Cycle (Lažánky and Sloup Lmst.): The second flooding was very strong and was recorded in sedimentary sequences by deposition of Amphipora ramosa facies with varieties based on occurrence of various brachiopod or gastropod faunas, containing also Dendrostella trigemme, Hillaepora rhiphaea and other corals (Lažánky Limestone, with little proportions 2-5 vol.% of the Josefov Bornhardtina onychophora facies). With eustatically controlled further rise of sealevel (and also slow but continuous subsidence of the basement), the muddy-ramp to lagoonal facies were successively replaced by upward thickened stromatoporoid-coral banks. The occurrence of Amphipora angusta is very typical for these intermediate parts, which are stratigraphically comparable with the 'Middle-varcus Zone'. This entire second transgressional complex is referred as the 'Býčí skála Cycle'. This cycle/parasequence terminated with a formation of widespread stromatoporoid-coral reef banks (and even patch reefs and some mounds), that formed a real cover of nearly all surface of the Moravian Block. The gradual replacement of Actinostroma heads by Trupetostroma skeleton-boulders is typical for the late stages, as well as great abundance of Stachyodes verticillata, Caliapora battersbyi or Wapitiphyllum laxum horizons. The Crassialveolites-Scoliopora assemblages (the Sloup Limestone) replaced the older Favosites and Heliolites corals, which greatly reduced both in abundance and diversity. Owing to above mentioned marker horizons in shallow water fauna, the termination of the 'Upper-varcus' reef banks has primary stratigraphical significance, although the sedimentary capping of this cycle was diversified according to length of respective hiatuses. [Note, please, that just these markers were formerly, in 2nd half of 20th century, mistakenly compared by many authors with the Gi-Fr boundary, which is correlated higher up today].

Ochoz Cycle (Habrůvka and Vilémovice Lmst.): The rest of Givetian time was recorded as a series of second-order eustatic pulses of generally little magnitude, that were coupled with subaerial weathering influences with karstification, as well as shallow truncations of paleosurfaces. The typical sediments are represented by thin varicolored blankets or lenses of the limestone. In depressions, such a 'black-vs.-white' color alternation of beds involves up to first tens of meters of limestone, which was referred by R. Burkhardt to so-called 'Transition Unit' (Býčí skála-Proplavaná skála-Rudice cave system). The caliaporids and typical Givetian amphiporids were much reduced and many of them experienced an almost global extinction. The next Frasnian highstand tracts were characterized by gradual but significant changes of the reef fauna. The Alveolites mailleuxi was gradually replaced by Alv. suborbicularis, and particularly, by diversified species of new and fast populated thick-walled alveolitids (Alveolites delhayei, Crassialveolites evidens, etc.). The Amphipora-banks of reef-barred lagoonal environments strongly differ from the all previous sediments with amphiporids. These Early to Middle Frasnian sediments have rich debris of Issinella green-algae thalli, Parathurammina foraminifers and the index species of these sediments is Amphipora laxeperforata. At least four partial highstand episodes were developed according to offlap-onlap movement (and maturation) of facies at the reef margin and separate patch reef zones in the backreef (maps, 3D cave profiling, and drilled sections). The lower part of this very complex cycle, where dark-colored and platy beds prevail, is formally referred as the Habrůvka Limestone, whereas the overlying light-colored and massive limestones (with bioherms and reefs) correspond to the type-facies of the Vilémovice Limestone. And the complete falsiovalis to jamiae Early to Middle Frasnian accretionary platform stack of stromatoporoid-coral banks, including also the latest Givetian sediments, is known under the name of the 'Ochoz Cycle'.

Mokrá Cycle (Hostěnice and Mokrá/Šumbera Lmst.): Close before the 'Lower rhenana-' or more exactly before the semichatovae-transgression, other period condensations and erosions occurred. On some places, effects of these partial lowstands were also accompanied by shedding of siliciclastics (Mokrá) or moderately developed quartz-sand spray that was exported even to the reef foreslope (Křtiny HV-105 borehole). The dark-colored lower part of this new carbonate cycle (the 'Mokrá Cycle') is typically marked by abundance of delicate Gracilopora-like corals, presently mostly but not always revised

Guidebook B2 'Moravian Karst' – p. 2

as Scoliopora tetralobata. The fourth repetition of amphiporid faunas is marked by Russian-Platform-related species (such as Amphipora tschussovensis or A. hanimeda), increased abundance of A. moravica but strongly decreased abundance of A. rudis. These dark-colored beds are referred as Hostěnice Limestone, but these 'dark layers' are much thinner in comparison with these three in older parts of the Moravian Karst limestones. Numerous outcrops of late Frasnian limestones in reef-related facies are concentrated in southern part of the Moravian Karst. The tectonic slices of Amphipora- and Stachyodes facies alternate the slope and basinal calciturbidites. With an exception for amphiporid-dominated facies of shallow or sheltered parts of ramps (Mokrá type), the all other sequences have good stratigraphic dating by conodonts (~ gigas, respectively rhenana and linguiformis Zs.). The limestones of reef-rim facies that made girdles around past elevations (and also sediments of upper-slope open ramp environments) have particularly numerous coral faunas with Alveolites tenuissimus, Thamnopora, Scoliopora, Allaiophyllum, Frechastraea pentagona, brachiopod coquinas, etc. Varying subfacies have abundant Stachyodes, Amphipora, Natalophyllum perspicuum and Solenoporaceae mixtures of additional faunal components, including also thick-shelled molluscs and/or fish remains (Šumbera, Lesní lom, etc. – Horákov type). This all stratigraphically late and mostly light colored limestone (in the above mentioned broad scale of subfacies from the exposed to relatively sheltered environments) have been aggregatively referred as the Mokrá Limestone. The successively offlaping phases of the terminal reefbank formation were abruptly cut by the Upper Kellwasser Horizon, when most of the benthic stromatoporoid-coral systems collapsed and amount of redeposited reef debris dramatically decreased. Numerous erosion lacunae and shallow-water recycling of sediments characterized the F-F situation on inner parts of the Moravian Karst carbonate platforms. The more continuous but much condensed sequences covered and bordered the epi-basinal zones. Relatively thick calciturbidite sequences (more than 10-15 m, founds of Homoctenus) are extremely rare and formed in partial troughs between the main platform massifs (e.g., allochthonous sediments in abandoned Bedřichovice Quarry, S of the Moravian Karst).

Post-Devonian rocks and geology

Famennian and Early Carboniferous limestones: The directly overlying complex of sedimentary bodies, if developed, is the Líšeň Formation (post-reef carbonate tempestites and turbidites). This formation developed during very long time interval, from the Early Famennian to Late Visean (~ 55 Ma). This formation casually draped the truncated margins of the abandoned (partly emerged) Devonian platform 'cake' and locally capped also the whole gravitationally sliding or tilted peripheral blocks of the Moravian Block. [~ Brunnia in its narrow sense; the Brunnia in its broad sense is, by Karel Zapletal from early 20th century, the whole group of East European microcontinents between Gondwana and Baltica].

On several places, these post-reefal carbonate sediments filled tectonic sags and erosional grooves or valleys in Devonian limestone basement. These sediments were never found directly on any type of crystalline basements. The Líšeň Formation contains many stratigraphic lacunae, which occur irregularly in time and space. The major groups of lacunae correspond to Early Famennian, Early Tournaisian and Early Visean lowstands. The Early Tournaisian offlaps are in great contrast with Middle Tournaisian onlaps. The Mid-Tournaisian sediments (on several places, e.g., Březina SW or Šošůvka W) filled the Frasnian-Tournaisian paleokarstic relief (caves and dolines). Several 'complex members' have been formally described: The thin-bedded, sedimentary condensed, micritic limestones with variegated color hues (if weathered) were called 'lenticular' Křtiny Limestone. [It is a really interesting fact, that this lenticular limestones were (and are) mostly normal thin bedded calciturbidites with smooth bedding planes, and were only changed by cleavage. The lenticular/nodular limestones of sub-sedimentary or early diagenetic origin are not so common as formerly assumed by geologists of 20th century. In addition, these limestones appear in several stratigraphical positions and form separate sedimentary bodies]. These facies developed typically in the upper and middle parts of carbonate slopes, on any place, if turbiditic flows were in their 'sedimentary bypass' zone. The normal grainstone to mud calciturbidites were accumulated in fans at the toe of the slopes (Hády-Říčka limestones). [The later formation is unlikely combination of Hády turbidites (Famennian-Tournaisian) and Říčka storm beds, tempestites to shallow turbidites (Tournaisian-Visean)]. The folded and stacked series of these deformed turbidite fans dominate the rock outcrops in the Mokrá and Lesní lom quarries (S Moravian Karst). The Visean foralgal tempestites and rudimentary patch reefs are relatively rare and eolian deposits (Dražovice Limestone) were discovered only in drilled rock cores in eastern subsurface of the Moravian oil-survey areas 'Mid-' and 'North-East'.

Visean flysch sediments: The Visean orogenic activity was recorded by the flysch sediments (Culmian Facies). Up to 0.7 km thick sequences (mostly separate fans fining and thinning upward and laterally toward the present north-northeast) were tectonically stacked, folded and rotated. Today, they form several kilometers thick relict massifs. Although some marginal 'Culm'-like sediments directly capped the platform margins, the major part of flysch was only tectonically juxtaposed with the platforms. The sediments in western Culmian nappes were deposited in forearc basins of huge Lugodanubian continental arc (in deep seas), whereas the deposits in the eastern segments have late flysch to molasse character and deposited during early collision stages between the Moldanubian-Lusatian parts of Gondwana and Brunnian parts of Laurussia. [True deep-sea flysch can never develop directly on the top of thick continental crust blocks capped by thick carbonate platforms. These blocks were partly cut from undercrusted Brunnia and partly belong to not-undercrusted parts of the foreland (Neoproterozoic nuclei).] Only the first meters of eastern Culmian formations contain Brunnia-related pebbles, whereas the main volumes were derived from deeply dissected active continental margin (up to mountain ridges after continental collision). Near Vyškov, we can huge boulders of granulites gneisses, a plenty of gneiss and also durbachite pebbles. As an exotic material, also exotic 'Kohlenkalk' pebbles occur (blackish, with Gigantoproductus, Litostrotion and Siphonodendron; Pindulka and Luleč). The up-slope grooves and canyons brought also deformed Devonian basinal shales, because of documents about Phacops trilobites in rare pebbles (Ruprechtov and Senetářov).

Guidebook B2 'Moravian Karst' – p. 3

Scattered younger relicts of sediments: Small relicts of Jurassic limestones are preserved in Paleogene halfgrabens, in the central and also southernmost parts of the Moravian Karst (Olomučany, Hády near Brno; Kellowayian to Kimmeridgian). A nice outcrop of the Late Jurassic transgression base (on folded Tournaisian Hády calciturbidites) is in the upper level of the Růžena Quarry on the Hády Hill (N margin of Brno). The Jurassic limestones deeply weathered during Cretaceous times and varicolored terrigenous Rudice Sands filled large karstic depressions. The Cenomanian quartz sandstones and silty claystones cap these sands near Olomučany, in central part of the Moravian Karst. This Cretaceous cover was probably never thicker than 0.2 km but was mostly eroded during the Late Cretaceous and Early Cenozoic times. Actually, this beginning of Tertiary times was significant for another karstification and formation of W-E directed canyons. Relict silcretes and quartzite pebbles (Eocene-Oligocene?), sandy fills of caves (Egerian-Eggenburgian), silty brown-colored clays (Ottnangian-Carpathian) and coral-bearing green-colored marine clays ('Tegel' Facies; Badenian) are scattered in karst valleys, dolines and caves on many places. And, of course, the Quaternary debris and loess (with alluvial plains and pebbly floodsheets) form the last sedimentary cover. [The loess sections with paleosols are on southeastern slopes of hills, e.g., Eastern Quarry of Mokrá].

Key references to bibliography

Galle, A. (1985): Biostratigraphy and rugose corals of Moravian Devonian, Czechoslovakia. – Newsletters on Stratigraphy, 14, 1, 48-68. Stuttgart.

Galle, A., Friáková, O., Hladil, J., Kalvoda, J. Krejčí, Z., Zukalová, V. (1988): Biostratigraphy of Middle and Upper Devonian carbonates of Moravia, Czechoslovakia. – Canadian Society of Petroleum Geologists, Memoir, 14, 3, 633-645. Calgary.

Hladil, J. (1994): Moravian Middle and Late Devonian Buildups: evolution in time and space with respect to Laurussian shelf. – Cour. Forsch.-Inst. Senckenberg, 172, 111-125. Frankfurt a.M.

Hladil, J. (1994): Microfacies of Devonian Limestones in Moravia: Part I. Approaches in Classification. – Zemní plyn a nafta, 38, 4, 291-335. Hodonín.

Hladil, J. (1994): Microfacies of Devonian Limestones in Moravia: Part I. Approaches in Classification. – Zemní plyn a nafta, 38, 4, 291-335. Hodonín. /and Part II. Review of Discerned Microfacies. – Zemný plyn a nafta, 39, 1, 19-70. Gbely.

Hladil, J. (2002): Geophysical records of dispersed weathering products on the Frasnian carbonate platform and early Famennian ramps in Moravia, Czech Republic: proxies for eustasy and palaeoclimate. Palaeogeography, Palaeoclimatology, Palaeoecology 181(1-3), 213-250. Amsterdam.

Hladil, J., Melichar, R., Otava, J., Galle, A., Krs, M., Man, O., Pruner, P., Čejchan, P., Orel, P. (1999): The Devonian in the Easternmost Variscides, Moravia: a Holistic Analysis Directed Towards Comprehension of the Original Context. –Abhandlungen der Geologischen Bundesanstalt, 54, 27-47. Vienna.

Zukalová, V. (1971): Stromatoporoidea From the Middle and Upper Devonian of the Moravian Karst. – Rozpravy Ústředního ústavu geologického, 37, 1-144. Prague.

Guidebook B2 'Moravian Karst' – p. 4

Fig. 1. Simplified Paleozoic stratigraphy with respect to Moravian Karst area and its lateral neighborhoods: a realistic look-up on the local situation with respect to time and space lacunae – © J. Hladil 2003, based on 1999 version for the book about Amateur Cave.

�����

Guidebook B2 'Moravian Karst' – p. 5

B2-EXCURSION – PROGRAM

Thursday Aug 07 : "Transport from Graz to Moravian Karst, Czech Republic": 13.00 AM - Leaving the conference city Graz, in direction Vienna, Brno, Adamov, Josefov. 7.00 PM - Arrival, accommodation. 8.00 PM - Dinner. The Pension "U kamenného kola", Josefov near Adamov, N of Brno. It will be our "Symposium Field Trip Center", we will sleep and dish there (four overnights and meals).

Friday Aug 08 : 8.00 AM Breakfast. Stop-1: Mokrá Quarries (Givetian to Visean). [1] -- on route, Žuráň Hill, Battle of Austerlitz, Dec 2, 1805 -- Field lunch. Stop-2: Lesní Quarry (Frasnian to Tournaisian, incl. F-F and C-D). [1] Stop-3: Skalka Quarry (Early and Middle Frasnian). [2] 8.00 PM - Dinner.

Saturday Aug 09 :

8.00 AM Breakfast. Stop-4: Býčí skála Cave and Kostelík Cave (Givetian). [3] Stop-5: Habrůvka Groove and Surrounding Outcrops (Givetian-Frasnian). [4] Field lunch. Stop-6: Výpustek Cave (Frasnian, Quaternary) and "Tora Bora" complex - never seen before (for 65 years!). [5] Stop-7: Jestřábí skála Cave (Frasnian). [4] -- on route, Křtiny Baroque Church, 1712, constr. J.B.A. Santini & Human Bone Chamber in the Cellar -- 8.00 PM - Dinner.

Sunday Aug 10 : 8.00 AM Breakfast. Stop-8: Punkva Cave and Macocha Abyss (Givetian). [6] Stop-9: Šošůvka Quarry (Frasnian and Tournaisian). [4] Field lunch. Stop-10: Vilémovice, Smrtní Cave and Kamenec Gorge (Frasnian). [4] Stop-11: Lažánky, Amphipora quarry. [4] -- on route, Josefov Metallurgy Museum -- 8.00 PM - Festive Dinner with Roast Pig -- Plenty of auxiliary stops can be arranged on place, if time will be spared --

Monday Aug 11: "Transport from Moravian Karst back to Graz, Austria": 8.00 AM Breakfast. 8.30 AM - Leaving the Field Trip Venue "U kamenneho kola". 2.30 PM - Arrival at Graz (through Vienna, about noon). In co-operation with the following companies and institutions: [1] Czech-Moravian Cement, Inc.; [2] Skalka Road Metal Co.; [3] Czech Caving Society; [4] Moravian Karst National Park; [5] Czech Army & Technical Museum; [6] Administration of the Moravian Karst Caves.

Guidebook B2 'Moravian Karst' – p. 6

Fig. 2. Location of the Excursion-B2 Stops: 1 – Mokrá, 2 – Lesní lom, 3 – Skalka, 4 – Býčí skála, 5 – Habrůvecký žlíbek, 6 – Výpustek, 7 – Jestřábí skála, 8 – Macocha, 9 – Šošůvka, 10 – Vilémovice, 11 – Lažánky.

�����

Guidebook B2 'Moravian Karst' – p. 7

B2-EXCURSION – STOPS

���

August 8 (Friday)

Stop-1: Mokrá Quarries

(Givetian, Frasnian, mainly Late Frasnian in outcrops of Quarry West, with continuation of sections up to Visean).

Outcrops: Huge excavation plants with several active and abandoned quarries, 3 km long, 7 levels (each about 15 m thick). About 15 km E of Brno. Southern part of the Moravian Karst.

Rocks & ages: Several slices of Paleozoic rocks form a pile at southern tectonic closure of the Moravian Karst. The slope and basin facies were thrust over relatively shallow-water facies of the Devonian. The latter facies crop out in the center of a north dipping faulted anticline and are exposed, in addition, in a separate block on the west. The Givetian Amphipora facies are only small erosion relicts. The Frasnian Mokrá facies assemblage consists of rhythmically deposited shallow water sediments, which range from beach-rock and loferite-like types to laminated grainstones and storm beds of proximal ramp environment. The complete Frasnian thickness is only about 100 m, and Late Frasnian consists of closely interspersed hardgrounds, laminites, Amphipora-banks and foralgal-facies grainstones/rudstones with stromatoporoid and coral fauna. The high-resolution correlations (magnetosusceptibility and natural gamma-ray stratigraphy) from the most recent times suggest, that banks with reef-fauna are preserved up to uppermost Frasnian levels, with an exception for absence of Pa. linguiformis sedimentary record. The onset of Pa. crepida sediments, with extraordinarily bedding parallel contact, is marked by cephalopod grainstones where is great abundance of small phosphorite pellets. The overlying Famennian sequence is condensed; encrinite horizons separate fine-bedded sets of micrite (lenticular/nodular limestone). The normal calciturbidite rhythmic sedimentation, where beds have planar surfaces, is typical for Late Famennian and developed above the dark-colored lenses of annulata limestone. Thick turbidite sequences of Famennian and Tournaisian age belong to allochthonous slices and blocks. The typical black cherty limestone and phosphorite breccias are Tournaisian, and higher in partial sections, the stratigraphy continues to Early Visean limestones and trilobite shales.

Examples of fossil benthic fauna: Tabulata – Caliapora battersbyi, Crassialveolites crassus [Givetian], Alveolites delhayei, Alveolites suborbicularis, Scoliopora denticulata, Scoliopora pulchra [Early to Middle Frasnian], Scoliopora denticulata, Sc. denticulata rachitiforma, Sc. vassinoensis, Sc. kaisini, Natalophyllum perspicuum, Syringopora volkensis, Aulostegites? sp. [Late Frasnian]. Rugosa – Tabulophyllum maria, Disphyllum veronika, Alaiophyllum jana [Late Frasnian]. Stromatoporoidea – Amphipora rudis, Amph. moravica, Amph. tschussoviensis, Amph. hanimedi, Actinostroma sp., Habrostroma? sp., Tienodictyon sp., Labechia cumularis, Atelodictyon sp., Stromatopora sp., Stromatoporella sp., Clathrocoilona sp. [Late Frasnian]. Foraminifera – Multiseptida corallina, Tikhinella fringa [Late Frasnian].

Comments: The previous conclusions about possible Early Famenian age of the latest banks with reef fauna must be withdrawn, in all probability, because the high-resolution sequence-log data provided very strong evidence of Late Frasnian age. It suggests, that indicative value of some faunal components (Labechia cumularis – Syringopora volkensis) is unclear and soakage with conodont elements of crepida-age from the 'Early Famennian disconformity' had to be much stronger than ever calculated. However, the Kellwasser Event horizon is most likely involved in the sequence as a hardground with brachiopod-coquina infills, that was covered by coral-stromatoporoid sheets (4 m below the hiatus). The Mokrá Quarry West provides unique Late Frasnian facies with Amphipora, Solenoporaceae and corals.

Curiosity: Late Tertiary (Eggenburgian – Badenian?) turtles and other land and marine fossils were found karst fills in NE corner of the Quarry West.

References:

Čejchan, P., Hladil, J. (1996): Searching for extinction/recovery gradients: the Frasnian-Famennian interval, Mokrá Section, Moravia, central Europe. – Geological Society Special Publication, 102, 135-161. London.

Dvořák, J., Friáková, O., Hladil, J., Kalvoda, J., Kukal, Z. (1987): Geology of the Paleozoic rocks in the vicinity of the Mokrá Cement Factory quarries (Moravian Karst). – Sborník geologických věd, Geologie, 42, 41-88. Praha.

Friáková, O., Galle, A., Hladil, J., Kalvoda, J. (1985): A Lower Famennian from the top of the reefoid limestones at Mokrá (Moravia, Czechoslovakia). – Newsletters on Stratigraphy, 15, 1, 43-56. Berlin-Stuttgart.

Hladil, J. (2002): Geophysical records of dispersed weathering products on the Frasnian carbonate platform and early Famennian ramps in Moravia, Czech Republic: proxies for eustasy and palaeoclimate. Palaeogeography, Palaeoclimatology, Palaeoecology 181(1-3), 213-250. Amsterdam.

Guidebook B2 'Moravian Karst' – p. 8

Stop-2: Lesní Quarry

(Mainly Late Frasnian in outcrops, with continuation of sections to Tournaisian, incl. F-F and C-D).

Outcrops: Abandoned quarry, partly conserved, partly filled. Length 0.5 km, 5 levels. Hády Hill outcrops are in close neighborhoods. Just the northern periphery of Brno. Southern part of the Moravian Karst.

Rocks & ages: The Middle Frasnian limestones with Amphipora rudis correspond to lee side of platform margin, whereas the Late Frasnian sediments have characters of exposed proximal ramps. The Late Frasnian is separated by an unconformity (boreholes in quarry area). Fine-bedded to laminated grainstones/rudstones of Late rhenana Zone are thinning and fining upwards. Numerous abrupt material alternations occur with the F-F boundary interval, where slight ferruginous oolite and siliciclastic admixtures are typical (at Klajdovka were oolitic iron ores). The Early Famennian beds of Pa. triangularis and crepida Zones are closely interspersed micrite and breccia layers. Their total thickness is very small, only 2–5 m, rarely more. In separate lenses, slices and blocks are preserved lime-mud sediments of marginifera Zone. Rare are light gray to yellowish lenses with accumulated shells of Clymenia. Very thick calciturbidite sequences of Pa. postera – trachytera Zones are mostly allochthonous, pushed over the rigid Frasnian limestone bodies. In a separate unit which was thrust over these structures is a thick Late Famennian to Tournaisian calciturbidite sequence. This sequence is strongly folded and sliced, but subhorizontal limbs locally preserved D-C successions with equivalents of Hangenberg shale, interval of pure laminated limestone, and onset of silty-clayey calciturbidites of Tournaisian age. Numerous faults modify the variscan deformation structures and many are very young (Cenozoic, Neogene).

Examples of fossil benthic fauna: Tabulata – Scoliopora denticulata, Sc. vassinoensis, Crassialveolites smithi, Alveolites elongatus, Thamnopora boloniensis langi [end-Middle Frasnian], Scoliopora tetralobata, Sc. relicta, Sc. kaisini, Sc. pulchra, Sc. denticulata vassinoensis, Sc. dent. rachitiforma, Egosiella gracile, 'Coenites' otavai, Alveolites tenuissimus junior, Crassialveolites domrachevi, Cras. multiperforatus, Cras. smithi, Alveolitella? sp., Aulopora sp., Aulostegites? sp., Thamnopora goselleti [Late Frasnian]. Rugosa – Frechastraea pentagona, Phillipsastraea? sp., Disphyllum sp., 'Neaxon' ? sp. [Late Frasnian]. Stromatoporoidea – Amphipora rudis, Hermatostroma sp. [end-Middle Frasnian], Amphipora moravica, Stachyodes lagowiensis, Actinostroma sp., Stromatopora sp., Clathrodictyon? sp. [Late Frasnian]. Foraminifera – Eonodosaria evlanensis, Eogeinitzina devonica, Nanicella evoluta, Nan. porrecta, Tikhinella fringa [Late Frasnian].

Comments: The slightly cacao-brownish crepida limestone contains also Styliolina-like shells and sometimes fragments of stromatoporoid coenostea. It is unclear, whether these bioclastic components have syndepositional age or were just redeposited with lithoclastic debris from underlying rocks. The Lesní lom represents the Horákov-Šumbera facies, which is very different from the Mokrá facies (50-60% difference only in benthic taxa). The necto-benthic and necto-pelagic faunas (sharks, fishes, conodonts, styliolinids and homoctenids, cephalopods are also very different and concentrated mainly in the first of these two facies. Numerous carbonized fragments of land plants occur in several bed intervals of Tournaisian calciturbidites (NE corner of the quarry).

Curiosity: The Late Tertiary (Eggenburgian – Badenian?) marine shelly fossils and endolithic borings were reported from fissures and caves on the periphery of Lesní lom.

References:

Hladil, J., Krejčí, Z., Kalvoda, J., Ginter, M., Galle, A., Beroušek, P. (1991): Carbonate ramp environment of Kellwasser time-interval (Lesní lom, Moravia, Czechoslovakia). – Bulletin de la Société géologique de Belgique, 100, 57-119. Bruxelles.

Kalvoda, J., Kukal, Z. (1987): Devonian-Carboniferous boundary in the Moravian Karst at Lesní lom Quarry, Brno-Líšeň, Czechoslovakia. – Cour. Forsch.-Inst. Senckenberg, 98, 95-117. Frankfurt A.M.

Stop-3: Skalka Quarry

(Early and Middle Frasnian).

Outcrops: Active quarry in forest N of Ochoz. Length 0.3 km, 6 levels. Southern part of the Moravian Karst.

Rocks & ages: The complex Ochoz Cycle is subdivided to at least four parasequences, which are marked with alternation of thin and dark-colored beds and thick beds of light-gray color hue. The latter beds are locally swelling up to form bioherms. Also the Middle/Late Frasnian times are marked with dark to blackish beds, where can be traced successions of coral and stromatoporoid faunas. The sediments are from back reef environments but not very distant from the exposed margins (great thickness and diversity of coral and stromatoporoid fauna).

Examples of fossil benthic fauna: Tabulata – Alveolites delhayei, Scoliopora denticulata, Alveolitella rarispinosa [Early Frasnian], 'Crassialveolites' evidens, Alveolites obtortus, Alv. suborbicularis, Scoliopora denticulata, Thamnopora boloniensis [Early Frasnian]. Rugosa – Thamnophyllum kozlowskii, Hexagonaria sp. [Early Frasnian], Thamnophyllum 'monozonatum', Thamnophyllum sp., Disphyllum sp., Peneckiella sp. [Middle Frasnian]. Stromatoporoidea – Actinostroma hebbornense, Act. devonense, Act. crassepillatum, Act. dehorneae, Amphipora pervesiculata, Amph. laxeperforata [Early Frasnian], Atelodictyon sphaericum spissum, Actinostroma dehorneae, Synthetostroma actinostromoides, Synthetostroma sp., Stromatopora sp., Taleastroma? sp., Hermatostroma longipillatum, Stachyodes lagowiensis, Amphipora rudis [Middle Frasnian].

Comments: The Quarry Skalka was during 1950-60s of 20th century known as 'Ochoz Hlubna' quarry. The rocks bodies known half century ago were mostly bioherms and thick biostromes and typical lagoonal bed series were subordinated. When

Guidebook B2 'Moravian Karst' – p. 9

the quarry progressed to N and NE, the relative volume of black-colored detritic banks much increased. It corresponds to space mosaic of biohermal complexes vs. well-bedded sediments from depressions of seafloor.

Curiosity: This locality was first investigated by Mrs. Vlasta Zukalová as early as during 1950s. She discovered and transported in her backpack large Stromatopora and Alveolites coral heads and determined the Frasnian age of rocks.

References:

Hladil, J. (ed.), Dvořák, J., Otava, J., Maštera, L., Růžička, M., Eliáš, M., Přichystal, A., Kalvoda, J. (1987): Documentation, originals of maps and explanatory text to Map sheet Mokrá-Horákov, 24-413, 1 : 25.000. – Czech Geological Survey, Unpublished Report, 120 pp., 5 map sheets, 45 diagrams, 7 mapping journals. Prague, Brno.

Zukalová, V. (1971): Stromatoporoidea From the Middle and Upper Devonian of the Moravian Karst. – Rozpravy Ústředního ústavu geologického, 37, 1-144. Praha.

���

August 9 (Saturday)

Stop-4: Josefov, Býčí skála Cave and Kostelík Cave

(nearly complete Givetian).

Outcrops: Caves and surface. Lower part of Křtiny Creek between Josefov junction and Vepřek Rock, main attention will be paid to Býčí skála Cave and Kostelík Caves, but several other caves are in close neighborhood (such as Evina, Brunina, or Bárová skála). Middle part of the Moravian Karst.

Rocks & ages: In shallow borehole (Josefov HV-104) were found erosional relict of the Čelechovice Cycle. This relict was covered by red paleosol and thin layer of sandstone. The second flooding and deposition of limestones was during Early Givetian. Sandy and marly dark-colored limestone (locally with mottled fabrics, little dolomitization) has worm tubes, rhapidopora, gastropods and first Hillaepora corals. Just above these sediments is the most common position of many Bornhardtina onychophora coquinas. The sediments above, with increased flooding of the basement, were changed to series of Amphipora ramosa beds. In these beds, up to three phases have certain cyclic recurrence (laminite, Amphipora-bed and boundstone); locally we can observe only alternation of laminite and beds with densely accumulated amphiporid stems. The homogeneity of this widespread facies development is disturbed only on some places, where elevations were covered by carbonate sands with hummocky-cross stratification and hardgrounds on amputated 'hummockies' were covered by large sheets of stromatoporid coenostea. The facies with Amph. ramosa gradually changes into overlying facies with Amph. angusta. Variety of transitions between these two facies can be observed both on the Býčí skála Rock and in the Cave. The adjacent Brunina Cave (at the chimney) display a section through micritic mound, where are Disphyllum and Amphipora patches, which are at least partly in original growth position. Matrix is relatively sterile, with an exception for large tower-like gastropods. The beds in the Amph. angusta facies are thickened upward, and finally change to real reef banks with coarse debris of corals and stromatoporoid fauna. This change is marked also by increased number of Stachyodes branches (all whole banks Stachyodes rubble). The end-Middle Devonian termination of reef facies is relatively sharp. The overlying interval of beds is thinner, dark-colored or composed of alternative light-and-dark continuation of beds (Late Givetian).

Examples of fossil benthic fauna: Tabulata – Caliapora venusta, Cal. battersbyi, Scoliopora dubrovensis, Sc. denticulata, Hillaepora dubatolovi, Hil. rhiphaea [Early to Middle Givetian], Crassialveolites crassus, Scoliopora denticulata, Caliapora battersbyi [Middle Givetian], Alveolites minutus, Crassialveolites mirus, Alveolitella fecunda, Caliapora battersbyi [end-Middle Givetian], Caliapora battersbyi, Scoliopora denticulata, Platyaxum? sp., Aulopora sp., Aulostegites? sp., Alveolites mailleuxi, Thamnopora bublichenkoi [Late Givetian]. Rugosa – Dendrostella trigemme [Early to Middle Givetian], Disphyllum wirbelauense, Lyrielasma sp. [Middle Givetian], Wapitiphyllum laxum [end-Middle Givetian], Disphyllum regulare [Late Givetian]. Stromatoporoidea – Actinostroma clathratum, Act. hebbornense, Act. devonense, Amphipora ramosa, Amphipora sp. [Early to Middle Givetian], Act. devonense, Act. papillosum, Act. crassepillatum, Amphipora angusta, Stachyodes verticillata [Middle Givetian], Trupetostroma mailleuxi, Tr. densum, Actinostroma dehorneae, Bifariostroma bifarium, Hermatostroma polymorphum, Idiostroma caespitosum, Sphaerostroma crassa, Stachyodes verticillata, Clavidictyon sp., Amphipora angusta [end-Middle Givetian], Stachyodes lagowiensis tenuicolumnaris, Stach. paralleloporoides, Idiostroma moravicum, Amphipora pervesiculata [Late Givetian].

Comments: The section between Josefov road junction and Kostelík Cave (with Bárová, Krkavčí a Býčí skála rock faces in center) is one of the most complete sections across the Givetian. However, several young faults complicated the correlation of beds among the segments, so that the most complete section continues directly upslope, along the Bárová to Krkavčí Rock. The Býčí skála Cave is paleontologically worthful locality, because the valleys of underground river (Jedovnice Brook) can serve as large polished sections with fauna (we can observe also Heliolites porosus and many other coralla and coenostea).

Curiosity: The Býčí skála Cave is known also as a sacrificial place of people from Hallstadt Period (1200–800 B.C.), where was found wheat, many select artifacts, and even human sacrifices ~ the last founds substantiated popular story about prince funeral. The sacrificial layer was capped by a thick but soft speleothem and large limestone blocks from ceiling of the cave.

Guidebook B2 'Moravian Karst' – p. 10

Old Ironwork of Josefov was built by duke Jan Adam Lichtenstein in 1732. This ironwork was closed at the end of 19th century, but Technical Museum placed here exhibitions about long history of metallurgy in these areas.

References:

Dvořák, J., Havlíček, V. (1963): Brachiopods of the 'Stringocephalus' limestones on the territory of Moravia. – Sborník Ústředního ústavu geologického, Geologie, 28, 85-99. Prague.

Hladil, J. (1983): The biofacies section of Devonian limestones in the Central part of the Moravian Karst. – Sborník geologických věd, Geologie, 38, 71-94. Praha.

Hladil, J. (1984): Tabulate corals of the genus Thamnopora Steininger from the Devonian of Moravia. – Věstník Ústředního ústavu geologického, 59, 29-39. Praha.

Stop-5: Habrůvka Groove and Surrounding Outcrops

(Middle/Late Givetian transitions).

Outcrops: Middle part of the Křtiny Creek between Josefov and Křtiny. Middle part of the Moravian Karst.

Rocks & ages: In close neighborhood of the locality are numerous outcrops of underlying limestones with Middle Givetian Amphipora angusta facies (Tři Kotle, Otevřená skála, etc.). The end-Middle Givetian limestones differ from the Kostelík Cave by occurrence of biostromes (or patch reefs). The continuation of light-and-dark alternation of beds is greatly exposed on the right side of Habrůvka Groove, where dark-gray laminated limestones deposited in lagoon are up to 25 m thick (Late Givetian up to ~ Givetian/Frasnian).

Examples of fossil benthic fauna: Tabulata – Caliapora battersbyi, Caliapora sp., Crassialevolites yunnanesis, Cras. mirus, Cras. grandis, Cras. crassus, Scoliopora denticulata, Sc. pulchra, Alveolites minutus, Alveolitella fecunda [end-Middle Givetian], Caliapora battersbyi, Alveolites mailleuxi, Alveolitella rarispinosa [Late Givetian]. Rugosa – Lyrielasma sp., Disphyllum wirbelauense, Disph. mariae, Disph. pashiense, Aristophyllum? sp., Sociophyllum tortuosum, Wapitiphyllum laxum [end-Middle Givetian], Thamnophyllum monozonatum, Thamn. kozlowskii, Disphyllum regulare [Late Givetian]. Stromatoporoidea – Trupetostroma mailleuxi, Tr. rectum, Tr. densum, Tr. cellulosum, Actinostroma dehorneae, Act. tabulatum crassum, Bifariostroma bifarium, Hermatostroma pustulosum, Her. polymorphum, Her. beuthii, Idiostroma caespitosum, Dendrostroma mutabile, Sphaerostroma crassa, Stachyodes verticillata, Stach. costulata, Stach. lagowiensis, Clavidictyon praecipuum, Clathrocoilona sp., Tienodictyon sp., Amphipora angusta [end-Middle Givetian], Stachyodes lagowiensis tenuicolumnaris, Stach. stromatoporoides, Idiostroma moravicum, Amphipora pervesiculata [Late Givetian].

Comments: The condensed beds on the top of biostrome '1071', in the roadcut, are wedge-shaped. In detail, the bedding shows thin lamellar or lens units with steep foresets. Prevailing material is fine debris amphiporids and corals. Abundance of truncations and brownish submarine hardgrounds can be explained by currents that washed the slope of this bioherm. The biohermal rocks on the opposite side of the valley (on the right side of Habrůvka Groove mouth) have up to 1 m large boulders of Hermatostroma.

Curiosity: In coral debris among those huge stromatoporoid coenostea, were found likely the youngest colony of Heliolites porosus of the whole Moravian Karst (and likely worldwide?).

References:

Hladil, J. (1981): The genus Caliapora Schlüter (tabulate corals) from the Devonian of Moravia. – Věstník Ústředního ústavu geologického, 56, 157-167. Prague.

Isaacson, P.E., Galle, A. (1991): Significance of Amphipora floatstones within the Lažánky Limestone (Late Givetian), Moravian Karst. – Věstník Ústředního ústavu geologického, 66, 5, 275-285. Prague.

Stop-6: Výpustek Cave

(Early/Middle Frasnian, with continuation of the sections to Late Frasnian; Quaternary fills in the cave)

Outcrops: Caves and surface. Upper part of the Křtiny Creek between Josefov and Křtiny, left slopes of the valley. Middle part of the Moravian Karst.

Rocks & ages: The area of Výpustek Cave displays rock and cave outcrops of the Frasnian lagoon with bioherms. Thick bedded and dark-colored beds prevail and major part of the cave system is just in this facies. In direction upslope and toward the west, the lagoonal complex is capped by light-gray colored limestones of late Middle Frasnian, where first Amphipora moravica occur. Further in this direction (Křtiny-Babice-Josefov road junction and hills above), a young wedge of Early rhenana limestones occurs, where banks with stromatoporoid-coral faunas are intercalated by open marine sediments (rare occurrences of conodonts, styliolinids and possibly homoctenids, nautiloids, fish remains).

Examples of fossil benthic fauna: Tabulata – Alveolites suborbicularis, Alv. mailleuxi, Alv. obtortus, Alv. donensis, Crassialveolites multiperforatus, Crassialveolites sp., Thamnopora boloniensis, Thamnopora sp., 'Placocoenites' ? sp., Tyrganolites frasnianus, Scoliopora pulchra, Sc. denticulata [Early/Middle Frasnian], Sc. tetralobata, Egosiella sp. [Late

Guidebook B2 'Moravian Karst' – p. 11

Frasnian]. Rugosa – Thamnophyllum kozlowskii, Thamnophyllum sp., Disphyllum regulare, Disphyllum sp., Peneckiella sp. [Early/Middle Frasnian], Phillipsastraea sp. [Late Frasnian]. Stromatoporoidea – Actinostroma dehorneae, Trupetostroma densum, Trupetostroma sp., Hermatostroma sp., Clathrocoilona sp., Stromatopora sp., Clathrodictyon? sp., Simplexodictyon? sp., Parallelopora sp., Stachyodes costulata, Stach. lagowiensis, Amphipora laxeperforata, Amph. rudis [Early/Middle Frasnian], Amph. moravica [Late Frasnian].

Comments: The rock faces in the cave are not very clear, because major parts of this cave were used for tens of years as underground manufactures and military objects (during and after the Second War). On relatively fresh rock surfaces, some cross-sections of Amphipora and Disphyllum can be studied, but rich treasures of reef fauna are in scree and debris on the slope of valley. The wet places in the cave are covered by thin yellow colored dripstone layer, where soot, particles from dust, fungi and bacteria coagulated into undulated stripes of black color – 'panther's skin'. The cave contains relicts of Quaternary sediments with abundant bones and skeletons of Pleistocene mammals. These fills were excavated due to abundant phosphorites and sold as fertilizer. A nice group of six complete skeletons of cave bear Ursus spelaeus (Jindřich Wankel in 19th century) originates from this cave. These skeletons are displayed in the Anthropos Museum in Brno-Pisárky.

Curiosity: Even during the 1930s, the Czechoslovak Army placed into Výpustek Cave an ammunition depot. During Second War (German Protectorate), the main cave corridors were considerably enlarged and an underground manufacture of aeronautical engineering was placed here. Only several years later (Communistic Government), this cave was changed to one of possible workplaces for military general staff. However, the parameters of this place are insufficient in modern times and the complex has recently been left. The Technical Museum of Brno is engaged in conservation of this object, and this local 'Tora Bora' can be open by public soon.

References:

Dvořák, J., Friáková, O., Galle, A., Hladil, J., Skoček, V. (1984): Correlation of the reef and basin facies of the Frasnian age in the Křtiny HV-105 borehole in the Moravian Karst. – Sborník geologických věd, Geologie, 39, 73-103. Praha.

Hladil, J. (1983): The biofacies section of Devonian limestones in the Central part of the Moravian Karst. – Sborník geologických věd, Geologie, 38, 71-94. Praha.

Stop-7: Jestřábí skála Cave

(Early to Middle Frasnian).

Outcrops: Surface and caves. Upper part of the Křtiny Creek between Josefov and Křtiny, right slopes of the valley. Middle part of the Moravian Karst.

Rocks & ages: After a period of partial lowstands during Late Givetian, the Early Frasnian flooding of carbonate platform caused deposition of black-colored lime-muds and Parathurammina or Issinella carbonate sands with numerous Amphipora laxeperforata horizons. With rising sea level, the seafloor relief of lagoon was diversified to bioherms and depressions. The both facies occur in small rocky cliffs of Jestřábí skála and mainly the dark-colored sediments contain abundant benthic fauna Although coralla of Alveolites mailleuxi and Thamnopora boloniensis are dominant, also brachiopods, gastropods and trilobites were found in scree and debris E of J.s. Rock. Reef margin of roughly comparable age (Ancyrodella rotundiloba, Anc. alata) was sampled by rock core of Křtiny HV-105 borehole only 2 km E of the J.s. Rock. There are two caves in the J.s. Rock, large Jestřábí skála Cave and small Cannibal's Cave.

Examples of fossil benthic fauna: Tabulata – Alveolites mailleuxi, Alv. suborbicularis, 'Crassialveolites' evidens, 'Placocoenites' ? sp., Scolipora denticulata, Egosiella sp., Thamnopora boloniensis, Thamn. micropora, Aulopora sp., Alveolitella sp. Rugosa – Thamnophyllum monozonatum, T. kozlowskii, Disphyllum wirbelauense, Disph. regulare, Disphyllum sp., Peneckiella sp., Grypophyllum? sp., Hexagonaria sp. Stromatoporoidea – Actinostroma dehorneae, Trupetostroma mailleuxi, Tr. densum, Hermatostroma sp., Clathrocoilona sp., Stromatopora sp., Clathrodictyon? sp., Simplexodictyon? sp., Parallelopora sp., Stachyodes costulata, Stach. lagowiensis, Amphipora laxeperforata, Amph. rudis.

Comments: Although the benthic fauna has mostly character of lagoon and moats (last with coatings of sediment by Clathrocoilona and 'Placocoenites'), some specific founds were made in neighborhood. For example, small (0.5 – 1 cm) sack-like coral-predators have complicated scaly exoskeleton and occur not only in the Moravian Karst, but also on distant basalt seamounts of Horní Benešov. Jestřábí skála and Canibal's caves provide also interesting founds of Pleistocene skeletal material (such as woolley rhinoceros: Coelodonta antiquitatis Blumenbach = Rhinoceros tichorhinus Cuvier).

Curiosity: The name of Cannibal's Cave originated due to human bones of Neolithic People, which have some evident traces after human teeth. Especially the Magdalenian population of hunters was well developed in the Moravian Karst, and they used these practices. Some of those people were well fixed to lucrative localities, but the other migrated through the Europe. For instance, a great collection of blades and instruments made from crystal of Alps originates was found in the Žitný Cave – Žitného jeskyně E of Jestřábí skála).

References:

Dvořák, J., Friáková, O., Galle, A., Hladil, J., Skoček, V. (1984): Correlation of the reef and basin facies of the Frasnian age in the Křtiny HV-105 borehole in the Moravian Karst. – Sborník geologických věd, Geologie, 39, 73-103. Praha.

Guidebook B2 'Moravian Karst' – p. 12

Hladíková, J., Hladil, J., Zusková, J. (1997): Discrimination between facies and global controls in isotope composition of carbonates: carbon and oxygen isotopes at the Devonian reef margin in Moravia (HV-105 Křtiny borehole). – Journal of the Czech Geological Society, 42, 1-2, 1-16. Praha.

���

August 10 (Sunday)

Stop-8: Punkva Cave and Macocha Abyss, northern part of the Moravian Karst.

(Early to Middle Givetian).

Outcrops: Caves and surface. Lower part of the Pustý žleb Canyon and the plain in the wedge between P.ž. and Suchý žleb canyons.

Rocks & ages: Close to junction of two karst canyons (Pustý žleb and Suchý žleb) is rocky cliff of Steigrovka Cave, where Early Givetian black-colored and clayey limestones have abundant Hillaeopora rhiphaea. These limestones are capped by thick sequence of Amphipora ramosa beds, which continue also to entrance and within the cave system of Punkva River (Punkevní jeskyně). The main wall of the Macocha Abyss (karst collapse structure) display a gradual transition from the Amph. ramosa dark-colored and relatively thin bedded facies to Amph. angusta facies (beds are thicker and lighter in comparison with previous). Dendrostella is gradually replaced by Temnophyllum and Disphyllum rugose corals. Just below the Upper Bridge (observation point above the abyss) are light-gray colored massive banks with Caliapora, stachyodids, actinostromids, and also algae (like Proninella).

Examples of fossil benthic fauna: Tabulata – Hillaepora rhiphaea [Early Givetian], Caliapora battersbyi, Cal. venusta, Crassialveolites crassus, Coenites simakovi [Middle Givetian]. Rugosa – Dendrostella sp. [Early Givetian], Temnophyllum sp. [Early/Middle Givetian], Disphyllum sp. [Middle Givetian]. Stromatoporoidea – Amphipora ramosa, Actinostroma stellulatum [Early Givetian], Amphipora angusta, Actinostroma dehorneae, Actinostroma tabulatum crassum, Pseudoactinodictyon sp., Bifariostroma bifarium, Stachyodes verticillata, Sphaerostroma sp. [Middle Givetian].

Comments: The Punkva Caves are only part of large Amateur Cave system that consists in total of more than 30 km of cave corridors. The part between Pustý žleb Canyon and Macocha Abyss (138 m to water level) was opened during 1909-1933 (dry levels 1909-1914 and watercourse 1920-1933), essentially by the members of the Brno Association of Cave Research, of course, following the ideas by Vladimír Josef Procházka (universal geologist but also serious coral expert) and using the great promotiveness and visions by Karel Absolon. Fresh rock faces (locally with scallops: scallops are spoon-shaped hollows dissolved in limestone floors, walls, and ceilings) between Water Domes and Lakes illustrates mainly dark-gray colored Givetian backreef facies, mostly with abundance of amphiporids, and some fabrics correspond to currents in past marine straits. Note that rims of the Macocha Abyss opening consists of two parts separated by fault, where the side opposite to Upper Bridge was uplifted (end-Middle Givetian vs. Early Givetian on this opposite side).

Curiosity: Directly at the karst spring of Punkva River (not at the Macocha Abyss), Prof. Jaroslav J. Jahn from Czech Technical College of Brno sampled the Amphipora ramosa specimens, which were used by Johannes Felix from Leipzig fro his important redescription of Amph. ramosa species in 1904-1905. The name Macocha means stepmother, which stars in a folk story related to this place.

References:

Čížek, P., Hladil, J. (1979): How old are the limestones forming the Main Wall of the Macocha karst collapse structure (in Czech). – Časopis Moravského Muzea, Vědy přírodní, 64, 13-16. Brno.

Hladil, J. (1983): Cyclic sedimentation in the Devonian carbonates of the Macocha Formation (in Czech). – Zemní plyn a nafta, 28, 1-15. Hodonín.

Stop-9: Šošůvka Quarry West

(end-Middle Frasnian and Tournaisian fills in cavities).

Outcrops: Abandoned quarry, only 0.2 km wide. The quarry is on the west of the Šošůvka municipality, in northern part of the Moravian Karst.

Rocks & ages: The northern end of the Moravian Karst is typical by reef complexes, which were considerably exposed to ocean. Huge accumulations of limestone contain many wild accumulations of Stachyodes rubble, and large stromatoporoid heads, presence of alveolitids and also crinoids also illustrate this type of environment. Similar sediments are also below the quarry, but beds in the quarry proper are Middle and end-Middle Frasnian (onset of Amphipora moravica, rare in this facies; Hermatostroma and Alveolites species). These Frasnian rocks were densely fissured and filled by complicated neptunian dikes of F-F to Middle Tournaisian ages. The veinlets and nests filled by sparite crystals of 'black appearance' are also very typical for these alternatively karstified and flooded marginal reef blocks (similarity to Winterberg reef of Harz). One of the Late Devonian caves was filled by Middle Tournaisian crinoidal limestone, volcanic tuffites of andesite-dacite composition, and

Guidebook B2 'Moravian Karst' – p. 13

continental siliciclastic material, with phosphorite nodules and pebbles. It indicates much different tectonic settings during the Tournaisian, i.e., ~ 30 Ma after the formation of the Frasnian Stachyodes reefs.

Examples of fossil benthic fauna: Tabulata – 'Crassialveolites' evidens, Crass. obtortus, Alveolites sp., Alveolitella sp., Scoliopora denticulata. Rugosa – Phillipsastraea sp., Thamnophyllum sp. Stromatoporoidea – Hermatostroma sp., Actinostroma dehorneae, Amphipora rudis, Amph. moravica, Sphaerostroma sp., Stachyodes lagowiensis, St. stromatoporoides, St. costulata [all groups ~ end-Middle Frasnian].

Comments: Behind the northern walls of this quarry is only Culm massif (Middle/Late Visean orogenic flysch unit, Protivanov Formation; geophysically documented step on this fault about 1 km). A thin stripe of Devonian limestones that continues toward the north contains only 5m (max. 30m) thickness of open-sea and slope sediments of the Frasnian, and, in addition, these calciturbidites did not provide any clastic or faunistic evidence of direct continuity with outer fans of the Šošůvka reefs. This geological structure reflects a long history of variscan reslicing and strike-slip faulting (in various, rotated fields of strain) and mainly superimposed young faults. The NW Moravian Karst (SW, and N of Sloup municipality) provides also the best outcrops of separate old Devonian sequences (often in separate tectonic units). From boreholes were recorded Emsian favositids, and great outcrops near Vavřinec exemplify the Late Eifelian reefs.

Curiosity: The largest paleocave with Tournaisian fills is known as 'Kater von Katzenstein Cave'. This name was derived in honor of Jaroslav Dvořák, who principally contributed the knowledge about these structures here. And it was a largely used nikname of this possibly biggest Moravian geologist of all times.

References:

Dvořák, J., Friáková, O. (1981): Paleogeography of Famennian and Tournaisian in the northern part of the Moravian Karst based on conodont faunas (in Czech). – Časopis pro mineralogii a geologii, 26, 3, 301-306. Prague.

Hladil, J., Bosák, P., Slavík, L., Carew, J.L., Mylroie, J.E., Geršl, M. (2003): A pragmatic test of the early origin and fixation of gamma-ray spectrometric (U, Th) and magneto-susceptibility patterns (Fe) related to sedimentary cycle boundaries in pure platform limestones. – Carbonates and Evaporites, 18, 1, 123-149. Troy NY.

Stop-10: Vilémovice, Smrtní Cave, Kamenec Gorge and neighborhoods

(nearly complete Frasnian, mainly Middle Frasnian in outcrops).

Outcrops: Star-like branching sections in area approximately 2 km long. The Kamenec Gorge, particularly the rocky escarpment above the road Vilémovice and road junction Vilémovice-Ostrov-Macocha. Northern part of the Moravian Karst.

Rocks & ages: The Late Givetian beds crop out in the opposite hill slope, toward Macocha, near the Srnčí Cave. There are several layers with Stachyodes verticillata rubble (Stachyodes Horizon by Radim Kettner), which are underlain by banks and mounds with Caliapora battersbyi. Similar Middle/Late Givetian stratigraphical situation was documented also in two vertical cave sections of Společnák and U Kříže dolines W of Vilémovice (on Harbechy Plain). Last occurrences of C. battersbyi on the left side of Kamenec Gorge are in the Ovčí Cave. After the Givetian/Frasnian disconformity, the Early Frasnian is represented by only 20–30 m of dark-gray colored and well-bedded limestone. The prevailing part of the Kamenec Gorge section show the Middle Frasnian limestone, where alternated dark and light colored lenses contain dish and cap like coralla of 'Placocoenites' sp. These beds are capped by thick banks with Stachyodes lagowiensis, layers with Alveolites and Thamnopora or bioherms and tongues of blocky material with Hermatostroma and Phillipsastraea. On the right side of this gorge (above road and above the Smrtní Cave), encrinites marks the end-Middle Frasnian levels. Relatively thin layer of Late Frasnian limestone, above, has gradual facies transition into Early Frasnian lime-mud facies (boreholes behind the edge of the escarpment). A similar type of F-F transition (= practically without visible markers of the Kellwasser events) was also documented by Zuzana Krejčí-Kesslerová 2 km toward SSW; abundant conodonts, but filled by trash and soil during 1990s.

Examples of fossil benthic fauna: [Frasnian from nearly base to nearly termination] Tabulata – Alveolites mailleuxi, Alv. suborbicularis, Alv. suborbicularis lamellosus, Alv. complanatus, Alv. donensis, Alv. obtortus, Alv. parvus, 'Crassialveolites' evidens, Alveolitella sp., 'Placocoenites' ? sp., Aulopora sp., Thamnopora boloniensis, Thamnopora micropora, Thamnopora striatoporoides?, Scoliopora denticulata, Sc. kaisini, Tyrganolites frasnianus. Rugosa – Thamnophyllum wirbelauense, Disphyllum carolinae, Thamnophyllum sp., Grypophyllum sp., Phillipsastraea sp., Tabulophyllum sp. Stromatoporoidea – Dendrostella mutabile, Stachyodes lagowiensis, Hermatostroma sp., Actinostroma dehorneae, Stromatoporella sp., Hermatostroma sp., Stromatopora sp., Clathrodictyon sp., Taleastroma sp., Atelodictyon sp., Amphipora pervesiculata, Amph. laxeperforata, Amph. rudis, Amph. moravica.

Comments: The rock walls at the Smrtní Cave shows nice stromatoporoid and coral fauna, but these fauna is largely deformed, so that formerly circular outlines are much elongated. This elongation is parallel with steep cleavage of regional significance (NNE-SSW – strike of planes), which is nearly perpendicular to bedding planes that are dipping to E. The appearance of 'subvertical false beds' is very suggestive, whereas the real (owing to cleavage undulated) bedding planes are hardly traceable in these massive coral banks. The sedimentary base of encrinites, which has sufficiently contrastive material, can illustrate this situation.

Curiosity: The Lopač sinkhole (in shallow karst valley between Vilémovice and Ostrov municipalities) show great outer reef facies of Middle/Late Frasnian age. Numerous conodonts and fish remains were dissolved on the stylolitic sutures among

Guidebook B2 'Moravian Karst' – p. 14

Guidebook B2 'Moravian Karst' – p. 15

light-gray colored limestone beds. These phosphatic insoluble residues form mm to cm-thick black colored sheets. Large and apiculate fish plates protrude from the corroded limestone in the underground river tunnel of Lopač cave system.

References:

Hladil, J. (1981): Alveolites corals from the Middle and Upper Devonian of the Moravian Karst (Anthozoa, Tabulata). – Časopis Moravského Muzea, Vědy přírodní, 66, 25-32. Brno.

Hladil, J. (1989): Function morphology of Alveolitinae and its dependence on the Kellwasser and other events (Tabulata, M. to U. Devonian, Moravia, CSSR). – Newsletters on Stratigraphy, 21, 1, 25-37. Berlin-Stuttgart.

Stop-11: Lažánky, Abandoned Amphipora-Quarry

(Early Givetian).

Outcrops: Small abandoned quarry less than 0.1 km long, margin of Lažánky village, right slope of the Lažánky Valley, northern part of the Moravian Karst.

Rocks & ages: The quarry is divided by an inclined fault in two different parts. The major part on the west contains a sequence of several tens of rhythms of shallow-water Amphipora ramosa limestones. The maximum abundance of Amph. ramosa and rare occurrences of Dendrostella trigemme correspond to late Early Givetian age (at least in regional context of stratigraphy in this part of Moravian Karst). Limestones were partly dolomitized, and larger dolomite crystals of smoky color hue were particularly placed after sparite crystals in the peripheral chambers of amphipora tissues.

Examples of fossil benthic fauna: Tabulata – Scoliopora dubrovensis, Hillaepora dubatolovi. Rugosa – Dendrostella trigemme, Temnophyllum? sp. Stromatoporoidea – Amphipora ramosa, Actinostroma sp.

Comments: The state of quarry in 1970s provided slightly less than 30 bedding planes, which were appropriate for documentation and measurement of preferential orientation of spaghetti-like accumulated amphipora stems. In times just before massive utilization of computer techniques a special optical methods was used. The miniaturized transparencies with thick marker lines made according to amphipora stems were studied in laser light to obtain Fraunhoffer diffractograms. These optical diffractograms provide a very interesting information about the patterns, i.e., preferential orientation including also information about size and spacing of these elongated bioclasts. Using the interpretation method by David Kobluk, the Devonian coastal line was stretched in NW-SE direction but slowly rotated during evolution of this sequence.

Curiosity: This valley is geologically very old (Paleogene). Under the present surface is a deep canyon filled with Tertiary (Badenian) marine clays. These clays contain numerous Badenian corals (Caryophyllidae 8%, Eupsammiidae 57%, Oculinidae 35%). The coral assemblages have complex character, where numerous oculinid fragments from fragile coralla on walls were mixed with eupsammiids that usually colonized the debris at the toe of these walls (Dendrophyllia). However, some of caryophylliids had to be swept also from very shallow levels (Acanthocyathus). And other corals are environmentally linked to deep or dark seafloor (Levipalifer). [List of species: Diplohelia moravica, Oculina sp., Trochocyathus affinis, Acanthocyathus vindobonensis, Caryophyllia sp., Coenocyathus taurinensis, Cc. degenerans, Cc. depauperatus, Dendrophyllia prismatica, Enallopsammia poppelacki, Eupsammia sp., Stephanophyllia imperialis, Deltocyathus (Levipalifer) sp.]. Badenian corals lived also in darkness of pre-Badenian caves (Svážná studna Cave, Eupsammia and Coenocyathus corals were embedded and covered by marine sediment fills with abundant foraminifers of the M5 Zone (Praeorbulina sicana – Pr. glomerosa). Two separate dm-layers of volcanic ash (from borehole) recorded huge volcanic explosions of undetermined Carpathian volcanoes.

References:

Hladil, J. (1985): Tabulate corals of the NP-824-Ostravice borehole: with special emphasis on variation of Scoliopora denticulata (in Czech). – Acta Universitatis Carolinae, Geologica, 3, 251-259. Prague.

Hladil, J., Hladil, K. (1981): A new diagnostic method for the preferential orientation in geology (in Czech). – Geologický průzkum, 7, 212-213. Praha.

Otava, J., Petrová, P., Hladil, J., Hladilová, Š. (2003): Finds of Badenian fossils in the cave Svážná studna, Moravian Karst: implications for speleogenesis (in Czech). – Geologické výzkumy na Moravě ve Slezsku v r. 2002, 25-30. Brno.

�����